Pay a visit to M.G Road, U.B city mall, Watson Road and the HAL Museum. The area around Cubbon Park is very green and pretty. Avoid going to the Tipu Sultan fort, commercial street and other such places, you'll be wasting your time there.
Nandi hills is a beautiful place near Bangalore which is approximately 60Km from Bangalore. You can enjoy the beautiful sunrise if you reach there befor 6 AM. The place will be covered with fog in the early morning which makes the place more beautiful. You can book a taxi from Bangalore to Nandi Hills(https://www.savaari.com/bangalore/bangalore-to-nandi-hills-cabs) and enjoy the trip.